The WarmlyYours TempZone Twin Radiant Floor Heating Roll TRT240-3.0x48 is constructed of a heating wire attached to a fiberglass mesh featuring cut and turn technology for full coverage as well as in-field flexibility. The fiberglass mesh that the wire is sewn to helps flatten the roll ensuring even heat and consistent spacing of the wires. The serpentine loop design delivers more heating capacity and faster floor warm-ups than most competitive systems. Less than 1/8" thick, it installs easily under tile, stone, hardwood and marble flooring.